A/C on hot days
 

I've noticed that my A/C takes a really long time to cool on really hot days, specially around noon. Sometimes I arrive at my destination having lost about a kilo in sweat. In the morning, the afternoon, at night, or on rainy days it doesn't have a problem freezing me to sub zero temperatures. The heater is working normally.

I was going to buy a recharge R134a+ bottle because I suspect it's a little low on gas. It's about $24 on any auto parts store. My local Pep Boys quoted me $50 for a diagnosis and a recharge/tint if necessary. So here I'm thinking, I might bite the bullet and save myself $26 or have it diagnosed. It's possible that the car has a refrigerant leak, but I think it is more likely it doesn't. I've been experiencing the same behavior for 2 years. In 2 years, if there was a leak, I'd expect it to have all been leaked out, therefore not cooling me to subzero temps when the ambient temps are a little more bearable.

Either way, I'm going to find out if I can get a cheaper diagnosis. What do you guys think?

Not knowing about how AC works, I'd be reluctant to just add R134 thinking it is 'low'. You can easily add too much and freeze the compressor causing all kinds of problems. I 'd at least get it checked out by a pro before adding a can of stuff from Autozone.

Are you using a window shade on the front windshield? If I don't on my STR, the dash gets so hot it seems as if it robs the AC of some efficiency.

In fact, I do use a window shade on the windshield. It helps by diminishing the temperatures inside the car when I get in it. The difference is that without it, it gets hot enough in there to bake a potato, and with it, it's just hot enough for me to break a sweat. The humidity here really doesn't help. I've actually opened my doors and found condensation on the door sills and gotten hit by a blast of water vapor.

I'll definitely be getting it checked out, but there isn't a power in the world, and no god in the universe, that is getting me to pay $50 for a diagnosis. It's not that I'm cheap, it's just that I have a student's budget.

I seem to remember something about codes, similar to OBDII but without a scanner. I think I read in this forum somewhere that the A/C unit in the car can spit out codes that can be displayed in the little screen to control the A/C temperature. Those codes could help diagnose problems with the refrigerant, compressor, etc.

I hope I didn't hallucinate that, because I'd be really nice to be able to save the money on the diagnosis with the codes. How does one go about getting the A/C screen to give me the error codes?

If you do the recharge make sure it has the gauge. Just take your time, and add a little at a time to allow it to cycle thru the system. Note some of the kits have a dye add to show possible leaks. If the dye shows a leak take to be serviced by a tech. The system will need to vacuumed , compressor oil and freon added. Hope it helps. Jim

I've actually performed the recharge on my dad's VDP a few years back. I'm familiar with the process. You're right, the gauge is the way to go with the recharge kit. I hadn't really thought much of the A/C on my car until he lent me his car when I was doing the tensioners on mine and I noticed that even in the hottest of days, the A/C on his VDP would blow snow.

I live in Dallas, TX where we can see temps of up to 115F or so and even on the hotest days my XKRs a/c will freeze you out. I suspect you need a recharge.

Mark

That's my initial thought.